# DragonFly Release 2.4

## Possible Upgrade Issues

* The kernel is unable to find the root and stops at the mountroot prompt.
  Due to the upgrade the drive may have changed names.
 * Hit scroll-lock on the console, scroll up and locate the root drive.
 * For BOOT+HAMMER try specifying: "hammer:xxxs1d", where xxx is the drive.
 * For UFS try specifying: "ufs:xxxs1a", where xxx is the drive.
 * Once you get the system up you may have to remount / read-write, then
   fix /etc/fstab and adjust /boot/loader.conf as necessary to specify
   the root mount using vfs.root.mountfrom="hammer:serno/SERIALNUMBER.s1d"
   (for example).
 * We recommend specifying mount points by serial number, using
   /dev/serno/SERIALNUMBER.s1PARTITION as necessary.  Also remember
   you may have a device specification in your /etc/rc.conf (for the dump device),
   and of course the root mount specification in /boot/loader.conf.

* Your kernel and world are out of sync.
 * ttys and ptys may not work properly in this case, you may have
   trouble getting a root prompt.
 * Try booting into single user mode and complete the installation.
 * Or boot the CD and re-upgrade.

* HAMMER-only installation fails with BTX errors or is unable to load
  the loader, or kernel.
 * An algorithmic bug in the loader's HAMMER implementation causes the
   loader to improperly parse file data in some cases.
 * All we can recommend here is to switch to a BOOT+HAMMER installation,
   which is fully supported and actually considerably easier to manage.
   An existing installation can be adjusted by stealing 256MB from your
   swap partition to create a UFS boot partition, naming it 'a'.  Then
   copy the HAMMER /boot into it (directly, not as a subdirectory called 'boot').
   Of course we'd prefer a completely clean install so the partitions are
   well ordered but stealing an 'a' partition from swap space will work
   if you can't afford to blow away the current drive.

* You have an AHCI SATA controller but the new AHCI driver is having
  problems detecting your drives.
 * There is a boot menu option to disable the AHCI driver, which will
   cause the kernel to fall back to the NATA driver.  Setting
   hint.ahci.disabled=1 in /boot/loader.conf will accomplish the same
   thing.

* The installer errors out while trying to install a disklabel.
 * Known issue.  We blew the partition cleaning dd.  Basically the
   installer wants to install a disklabel64 but there is a standard
   disklabel already installed.  For safety reasons the disklabel
   program refuses to blow away the old label.
 * You can blow away the whole disk or the slice from the emergency
   shell prompt (alt f3? alt f4?) and then start the installation over
   again.
 * dd if=/dev/zero of=/dev/RAWDISK bs=32k count=4 **This will blow
   away the whole disk**.  You can try it on just the slice, aka
   RAWDISKs1 but it is fairly dangerous to do so be careful.

## Installer Issues

* When installing w/ VMWare we recommend selecting a SCSI disk controller
  and using the CD ISO, not the DVD ISO.

* When installing w/ VirtualBox we recommend defaults but select a hard
  disk size at least 3G and use the CD ISO, not the DVD ISO.

* VirtualBox (and maybe VMWare too) do not implement the hard disk
  synchronize_cache command so a panic or hard shutdown may corrupt
  the filesystem.  Because of this and also the fact that most
  user-specified hard drives are not the 200GB minimum recommended
  for HAMMER, we recommend that you install UFS on the virtual
  hard drive and not HAMMER.

* **GUI ISO (2.4.0 only)** installs a bad /boot/beastie.4th file which will
  cause a HAMMER install on the HD boot to fail.  You can fix
  this by booting from the DVD again, logging in as root,
  mounting /dev/ad0s1a /mnt  (or da0s1a or whatever the hard
  drive winds up being), and editing /mnt/beastie.4th.  Please
  remove the /boot prefix from the two include lines near the
  top.  They should read:  'include screen.4th' and 'include frames.4th'.

* **When to install UFS** - A HAMMER setup (actually BOOT+HAMMER) is
  the default installation but users with hard drives less then 50GB should
  probably select a UFS install instead of HAMMER.  HAMMER is designed
  for larger hard drives, not tiny little hard drives or small virtual drives.
  Users who insist on using HAMMER on a small drive anyway should at least
  'chflags nohistory /usr/obj /var/crash'.

## Issues in 2.4.0 which are fixed in 2.4.1

* Issues with kqueue and SIGIO not working properly on pipes
  have been fixed.  This issue affected numerous programs
  including postfix, dovecot, and others, which use pipes and
  kqueue for I/O notification.
* 64-bit kernels were unable to probe USB mass storage devices.
* cdrecord sometimes paniced after burning completed.
* Kernel failed to finish CAM probes during boot.
  (Note that some drivers may still register their CAM busses too
  late, and this problem has not yet been tracked down).
* Manual pages specified with relative paths which include a
  directory component did not work.
* Misc. setuid/setgid issues with exec and [f]chdir, operations
  sometimes failed.
* Installer's beastie.4th (boot loader issues) have been corrected.
* Boot loader now contains real-mode fixes which may improve booting
  from USB memory sticks.
* tcsh updated (fixes incorrect default autologout settings)
* Added support for VIA Nano and VIA C7
* Added support for probing OpenBSD slices
* Misc manual page improvements.

People can checkout the release branch and compile up a new kernel
at any time, or wait for the incremental release.

## IRC Help

There are usually DragonFly users and developers on EFNet in the
 #dragonflybsd channel who can help you if you have questions or
problems.